[0001] This invention relates to water-soluble mixtures of water-soluble, fiber-reactive,
yellow azo dyestuffs, which have superior colour yield and improved build-up properties.
Colour yield as used in this specification is the amount of colour spectrally measured
in standard colour density units imparted by the dyestuff to a fabric or other substrate.
Build-up is the ability of a dyestuff to continue to yield deeper or darker shades
of a colour as the concentration of the dyestuff in the dye bath is increased which
is also expressed in colour density units.
[0002] Typically, the colour yield of an admixture of azo-dyestuffs is proportional to the
colour yield and the amount of the components in the mixture. In general the colour
yield of a mixture will not exceed the colour yield of the strongest component of
the mixture. Surprisingly, we have found that the colour yield of the azo dyestuff
mixtures of this invention are significantly higher than the colour yield of individual
components. Secondly, these mixtures of the invention have improved build-up properties
over the individual components.
[0003] An exception to this general rule is already reported in British Patent Specification
2,108,141 wherein certain mixtures of blue monoazo dyes, which, however, represent
disperse dyes, are reported having good build-up properties and high tinctorial strength
superior to the effect achieved by the application of any single component of the
dye mixture. Also U.S. Patent Specification No. 4,548,613 reports that certain mixtures
of yellow monoazo disperse dyes (C.I. Disperse Yellow 54 and 64) produce dyeings of
high tinctorial strength and high dye bath exhaustion, and U.S. Patent Specification
No. 4,427,413 discloses other mixtures of these same disperse dyes with improved build-up
and better yields in transfer printing. Although these exceptions to the general rule
report improved higher color yield or other improved properties they are exceptions.
[0004] According the present invention, it has now been found water-soluble compositions
(mixtures) of fiber-reactive, yellow azo dyestuffs, comprising a first and a second
azo dyestuff conforming to the general formula (1)

wherein
R is each independently selected from alkyl of 1 to 4 carbon atoms and alkoxy of 1
to 4 carbon atoms and hydrogen, preferably from alkyl of 1 to 4 carbon atoms and alkoxy
of 1 to 4 carbon atoms, with the proviso that at least one of said R moieties is selected
from alkyl of 1 to 4 carbon atoms in at least one of said both dyestuffs and that
each of said both dyestuffs contains at least two R moieties selected from alkoxy
of 1 to 4 carbon atoms,
X is vinyl or is a group of the general formula -CH2-CH2-Z , in which
Z is chlorine, bromine, sulfato, thiosulfato, phosphato or alkyl-amino with an alkyl
of 1 to 4 carbon atoms, or dialkyl-amino with alkyls each having independently 1 to
4 carbon atoms, and
M is hydrogen or preferably an alkali metal, such as sodium, potassium or lithium,
which compositions (mixtures) according to the invention of said first and second
dyestuffs have, upon application on materials as indicated below, a superior colour
yield value than the individual first or second dyestuff of the mixture and improved
build-up properties, as indicated at the begin of the instant specification.
[0005] The moiety X in said dyestuffs is preferably vinyl or in particular B-sulfatoethyl.
[0006] The terms sulfo, sulfato, thiosulfato and phosphato (respectively sulfo group, sulfato
group, thiosalfato group and phosphato group) means groups of the general formula
-SO
3M , respectively -OS0
3M or -S-S0
3M or -OPO
3M
2 , in which M is defined as above.
[0007] The ring substituents in the above general formula (1) may be selectively positioned
on the rings readily apparent to one skilled in the art. Preferably, the substituents
R are in the 2,5- and 2',5'-position and the M0
3S- and -S0
2-X moieties in the 4- and 4'-positions, respectively. Other illustrative isomers have
the following ring positions:
R in 2,5- and 2',5'- and M03S- and -S02-X in 3- and 3'-positions, respectively;
R in 2,4- and 2',4'- and M03S- and -S02-X in 5- and 5'-positions, respectively;
R in 3,5- and 3',5'- and M03S- and -S02-X in 2- and 2'-positions, respectively;
R in 2,4- and 2',5'- and M03S- and -S02-X in 5- and 3'-positions, respectively.
[0008] However, regardless of the isomeric position of the ring substituents, the acetoacetamide-azo
chromophore of general formula (1) will give a yellow dyestuff. The shade or tone
of the yellow dyestuff being dependent upon the type and position of the ring substituents.
[0009] The azo dyestuff mixtures of this invention are useful in colouring and printing
fibers and other materials, such as leather, which contain carbonamide (-CO-NH-) and/or
hydroxy (-OH) groups. They provide brilliant yellow shades, in particular on cellulosic
materials, and the dyeings show improved color yield, build-up and fastness properties.
[0010] The individual dyestuffs are known from U.S. Patent Specification No. 3 519 616 and
from European Application Publication No. 0 122 599 A or may be prepared analogously
and in conventional manner, such as by coupling a n-aceto- acetyl derivative of an
alkyl and/or alkoxy substituted aniline sulfonic acid with the corresponding diazotized,
fiber-reactive aniline. The coupling reaction is carried out under conventional conditions
for the preparation of fiber-reactive azo compounds, e.g. in an aqueous medium, at
a temperature between 0°C and 30°C, preferably 5°C and 15°C, and at a pH between 3
and 8, preferably between 4 and 7. Although the following Examples use the procedure
of preparing each dyestuff separately and then mixing the components, it is apparent
that the diazotization and coupling reactions can be sequentially conducted in admixture.
[0011] After preparation, the dyestuff may be isolated as a powder, either by salting it
out of solution or by spray drying, and brought to standard strength by the addition
of an inorganic salt. Advantageously, the prepared dyestuff may be recovered as a
liquid composition which can be brought to a standard strength by the addition of
water. Alternatively, the standardization of the dyestuff mixture may be carried out
after mixing the individual components.
[0012] Preferred mixtures of this invention are as follows, containing dyestuffs of the
following formulae (in which M are defined above, preferably being Na or K):
Mixtures I
[0013] comprising Dyestuffs (A) and (B):

Mixtures II
[0014] comprising Dyestuffs (A) and (C):

[0015] These dyestuff mixtures (Mixtures I and Mixtures II) may contain 95 % to 5 % by weight
of Dyestuff (A) and 5 % to 95 % by weight of Dyestuff (B), preferably 80 % to 20 %
by weight of Dyestuff (A) and most preferably 60 % to 40 % by weight of Dyestuff (A).
[0016] The dyestuff percentages are calculated on the total amount of both Dyestuffs (A)
and (B).
[0017] It also is understood that the mixed dyestuffs of this invention may be used in conjunction
with other dyes.
[0018] Another preferred mixture of the invention is
[0019] Mixture III comprising Dyestuffs (B) and (C):
In Mixture III, Dyestuff (B) may be present in an amount of 95 to 80 % by weight,
preferably 90 % to 80 % by weight and most preferably 87 to 83 % by weight, calculated
on the total amount on both Dyestuffs (B) and (C). However, when the concentration
of Dyestuff (B) is reduced to less than about 80 % by weight a determinmental effect
in colour yield is observed.
[0020] The dyestuff mixtures of the present invention are in particular suitable for the
dyeing of cellulosic materials, such as cotton, linen, viscose rayon and staple fibers.
They can be applied by any one of the usual dyeing and printing methods for fibre-reactive
dyestuffs and they yield on cellulosic materials, in the presence of alkaline agents,
brilliant yellow shades having excellent fastness properties, and particularly superior
colour yield and build-up in both exhaust and continuous dyeings. The present dyestuff
mixtures may also be used on other fibers containing reactive groups e.g. wool, silk
or polyamide fibers.
[0021] The following Examples further illustrate this invention. The percentages and parts
are by weight unless noted otherwise.
Example 1
[0022] This Example illustrates the preparation of Dyestuff (B): 65.0 parts of 4-B-sulfatoethylsulfonyl-2-methoxy-5-methylaniline
were dissolved in 200 parts of water at 35°C and at a pH of 5.5 to 6.0 by the addition
of 13 parts of sodium carbonate. The resulting solution was cooled to 0 to 5°C with
ice, and 50 parts of 31 % hydrochloric acid were acid. The slurry was diazotized by
the addition of 35 parts of an aqueous 39.5 % sodium nitrite solution. The excess
nitrite was decomposed by the addition of 1 part of sulfamic acid. 10 parts of a conventional
filter aid were added and the diazo solution was clarified and added to an aqueous
solution containing 60.2 parts of 2-methoxy-5-methyl-4-sulfo-acetoacetanilide while
maintaining the pH at 4.5 to 5.0 by the addition of 15 parts of sodium carbonate.
The resulting dyestuff solution was warmed to 50°C and the dyestuff salted out by
the addition of 300 parts of sodium chloride. After filtration and drying, 143.1 parts
of a dyestuff product were obtained containing 89.5 % of Dyestuff (B) (the residual
parts representing mainly electrolyte salts such as sodium chloride). The 143.1 parts
so obtained were blended with 77.0 parts of anhydrous sodium sulfate to yield 220.1
parts of dyestuff powder having a conventional standard strength (content of Dyestuff
(B): 58.2 %).
Example 2
[0023] This Example illustrates the preparation of Dyestuff (A): 68.2 parts of 4-B-sulfatoethylsulfonyl-2,5-dimethoxyaniline
were dissolved in 320 parts of water at a pH of 6.0 to 6.5 by the addition of 14 parts
of sodium carbonate. 28 parts of kieselguhr, 8 parts of Fuller's Earth and 4 parts
of activated charcoal were added and the solution clarified. The filter cake was washed
with 100 parts of water. 28 parts of a 93 % sulfuric acid were added, the solution
iced to 0 to 5°C and diazotized with 33.8 parts of an aqueous 40.1 % sodium nitrite
solution. The excess nitrite was decomposed by the addition of 1 part of sulfamic
acid. The diazo solution was then added to a solution containing 56 parts of 2-methoxy-5-methyl-4-sulfo-
acetoacetanilide while maintaining the pH at 4 to 5 by the addition of 16 parts of
sodium carbonate. The resulting solution was spray dried to yield 188.3 parts of dyestuff
product containing 70.3 % of Dyestuff (A). The 188.3 parts of dyestuff so obtained
were blended with 125.5 parts of anhydrous sodium sulfate to yield 313.8 parts of
dyestuff powder of a conventional standard strength (content of Dyestuff (A): 42.2
%).
Example 3
[0024] This Example illustrates the preparation of the yellow monoazo Dyestuff (C):
102.3 parts of B-sulfatoethylsulfonyl-2,5-dimethoxyaniline were dissolved in 480 parts
of water by the addition of 20.4 parts of sodium carbonate. 42 parts of kieselguhr,
12 parts of Fuller's Earth and 6 parts of activated charcoal were added and the solution
clarified. The filter cake was washed with 150 parts of water. 42 parts of 93 % sulfuric
acid were added, the solution cooled to 0 to 5°C with ice, and diazotized by the addition
of 51 parts of an aqueous 40 % sodium nitrite solution. The excess nitrite was decomposed
by the addition of 1 part of sulfamic acid. The diazo solution was then added to a
solution containing 88.8 parts of 2,5-dimethoxy-4-sulfo-acetoacetanilide and maintaining
the pH at 4 to 5 by the addition of 28 parts of sodium carbonate. The resulting solution
was spray dried to yield 300 parts of dyestuff product with 65.7 % of Dyestuff (C).
The 300 parts so obtained were blended with 200 parts of sodium chloride to yield
500 parts of dyestuff powder of a conventional standard strength (content of Dyestuff
(C): 39.4 %).
Examples 4 to 6
[0025] The following Examples 4 to 6 were prepared by mixing the dyestuff powders of adjusted
standard strength of Examples 1 to 3 in the proportions indicated and applied to test
fabrics using a standard exhaust dyeing procedure. The colour yield on the dyed test
fabrics were analyzed using a spectrophotometer, computer assisted system and determined
in colour density units. The Colourant reported in the Examples is weight percent
of dyestuff of standard colour strength based upon the weight of the test fabric in
the dye bath.
[0026] The following exhaust dyeing procedure was used in preparing the dyed specimens upon
which colour measurements were determined. A 20:1 boiled-off, cotton yarn knitted
into socks was used as the fabric. Prior to dyeing the fabric was scoured in an aqueous
solution of a commercial scouring agent at a concentration of 0.5 grams per liter
for 5 minutes at the boil and then rinsed with hot water.
[0027] A dye bath solution was prepared at 80°F (about 27°C). It contained 1.0 % based upon
the weight of the test fabric of a polyphosphate sequestering agent of the neutral
type, common salt, soda ash, caustic soda, and dyestuff. The dyeings
'were conducted a 1:10 liquor ratio.
[0028] An amount of salt (sodium chloride), soda ash and caustic soda were added in each
dyeing depending on the total concentration of the dyestuff in the dye bath according
to the following schedule:

[0029] The dye bath solution and test specimen were sealed in metal cans, heated to 140°F
(60°C) under agitation at a rate of 2°F (1°C) per minute and held at 140°F (60°C)
for 45 minutes. After completing the 45 minutes-dyeing period, the specimens were
rinsed with cold running tap water until bleeding stopped. They were then neutralized
with a 1 % solution of acetic acid (56 % strength) for one minute at 160°F (about
70°C), washed with a 0.25 % soap solution for 3 minutes at 200-210°F (93-99°C), rinsed
for five minutes at 160°F and dried. The term liquor ratio as used in the foregoing
description is the weight ratio of fabric to dye bath solution.
[0030] Dyeings were prepared by the foregoing procedure using the individual component dyestuffs
and mixtures of the dyestuffs. The results are as follows. Colour yield is reported
in colour density units (CDU).
[0031] The actual dye content of the Colourants used in the following Examples were as follows:
Ex. 1 Dye - 58.2 %; Ex. 2 Dye - 42.2 %; Ex. 3 Dye - 39.4
Example 4
[0032]

Example 5
[0033]

Example 6
[0034]

Examples 7 to 9:
[0035] The following Examples 7 to 9 were at a 4 % dyestuff concentration, and Example 10
at a 2 % dyestuff concentration, using varying percentages of the individual components
in an exhaust dyeing.
Example 7:
[0036]

Example 8:
[0037]

Example 9:
[0038]

Example 10:
[0039]

The dyestuff mixtures of this invention may also be prepared and used as liquid dyestuff
solutions of standard colour strength. Preferably, these liquid dyestuff compositions
should be adjusted to a pH of about 2.5 to about 4.5 to provide maximum storage stability
and dye performance properties. These compositions also should be substantially free
of buffer substances.
1. A water-soluble mixture of monoazo dyestuffs comprising a first and a second azo
dyestuff conforming to the general formula (1)

wherein
R is each independently selected from alkyl of 1 to 4 carbon atoms and alkoxy of 1
to 4 carbon atoms and hydrogen, with the proviso that at least one of said R moieties
is selected from alkyl of 1 to 4 carbon atoms in at least one of said both dyestuffs
and that each of said both dyestuffs contains at least two R moieties selected from
alkoxy of 1 to 4 carbon atoms,
X is vinyl or is a group of the general formula -CH2-CH2-Z , in which
Z is chlorine, bromine, sulfato, thiosulfato, phosphato or alkyl-amino with an alkyl
of 1 to 4 carbon atoms, or dialkyl-amino with alkyls each having independently 1 to
4 carbon atoms, and
M is hydrogen or preferably an alkali metal.
2. A dyestuff mixture according to Claim 1, wherein the moieties R are in 2,5- and
2',5'-positions, the group -S02-X is in the 4'-position and the group M03S- in the 4-position.
3. A dyestuff mixture according to Claim 1 or 2, wherein R is each independently selected
from alkyl of 1 to 4 carbon atoms and alkoxy of 1 to 4 carbon atoms, with the proviso
that at least one of said R moieties is selected from alkyl of 1 to 4 carbon atoms
in at least one of said both dyestuffs and that each of said both dyestuffs contains
at least two R moieties selected from alkoxy of 1 to 4 carbon atoms.
4. A dyestuff mixture according to any one or more of Claims 1 to 3, wherein Z is
sulfato.
5. A dyestuff mixture according to Claim 1, wherein said first monoazodyestuff has
the formula (A)

and said second monoazodyestuff has the formula (B)

wherein M is defined as in Claim 1.
6. A dyestuff mixture according to Claim 1, wherein said first monoazodyestuff has
the formula (A)

and said second monoazodyestuff has the formula (C)

wherein M is defined as in Claim 1.
7. A dyestuff mixture according to Claim 1, wherein said first monoazodyestuff has
the formula (B)

said second monoazodyestuff has the formula (C)

wherein M is defined as in Claim 1, and wherein Dyestuff (B) is present in an amount
from 95 % to 80 % by weight, calculated of the total amount of (B) and (C).
8. A dyestuff mixture according to Claim 5, wherein said Dyestuff (A) is present in
an amount from 80 % to 20 % by weight, calculated of the total amount of (A) and (B).
9. A dyestuff mixture according to Claim 5, wherein said Dyestuff (A) is present in
an amount from 60 % to 40 % by weight, calculated of the total amount of (A) and (B).
10. A dyestuff mixture according to Claim 6, wherein said Dyestuff (A) is present
in an amount from 80 % to 20 % by weight, calculated of the total amount of (A) and
(C).
11. A dyestuff mixture according to Claim 6, wherein said Dyestuff (A) is present
in an amount from 60 % to 40 % by weight, calculated of the total amount of (A) and
(C).
12. A dyestuff mixture according to Claim 7, wherein said Dyestuff (B) is present
in an amount from 90 % to 80 % by weight, calculated of the total amount of (B) and
(C).
13. A dyestuff mixture according to Claim 7, wherein said Dyestuff (B) is present
in an amount from 87 to 83 % by weight, calculated of the total amount of (B) and
(C).
14. An aqueous liquid dyestuff composition comprising 25 to 50 weight % of a mixture
of dyestuffs according to one or more of Claims 2 to 13, 0 to 10 % by weight of an
inorganic electrolyte salt and 50 to 75 % by weight of water, said liquid dyestuff
composition having a pH of about 2.5 to 4.5 and being substantially free of buffer
substances.
15. An aqueous liquid dyestuff composition comprising 25 to 50 % by weight of a mixture
of dyestuffs according to Claim 5, and 50 to 75 % by weight of water, said liquid
dyestuff composition having a pH of about 2.5 to 4.5 and being substantially free
of buffer substances.
16. An aqueous liquid dyestuff composition comprising 25 to 50 % by weight of a mixture
of dyestuffs according to Claim 6, and 50 to 75 % by weight of water, said liquid
dyestuff composition having a pH of about 2.5 to 4.5 and being substantially free
of buffer substances.
17. An aqueous liquid dyestuff composition comprising 25 to 50 % by weight of a mixture
of dyestuffs according to Claim 7, and 50 to 75 % by weight of water, said liquid
dyestuff composition having a pH of about 2.5 to 4.5 and being substantially free
of buffer substances.